#include<stdio.h>
typedef struct TreeNode {
	int val;
	TreeNode* left;
	TreeNode* right;
}TreeNode;
int maxDepth(struct TreeNode* root) {
	if (root == NULL) {
		return 0;
	}
	if (root->left == NULL && root->right == NULL) {
		return 1;
	}
	int x1 = maxDepth(root->left);
	int x2 = maxDepth(root->right);
	return x1 >= x2 ? x1+1 : x2+1;
}
int main()
{
	return 0;
}